title: Hypericum triquetrifolium-Derived Factors Downregulate the Production Levels of LPS-Induced Nitric Oxide and Tumor Necrosis Factor-α in THP-1 Cells.
abstract: Based on knowledge from traditional Arab herbal medicine, this in vitro study aims to examine the anti-inflammatory mechanism of Hypericum triquetrifolium by measuring the expression and release of pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukine-6 (IL-6), and inducible nitric oxide synthase (iNOS) in human monocytic cells, THP-1. The effects were assessed by measuring the levels of secretory proteins and mRNA of TNF-α and IL-6, the levels of nitric oxide (NO) secretion and the expression of iNOS in THP-1 cells. Cells were treated with 5 μg lipopolysaccharide/ml (LPS) in the presence and absence of increasing concentrations of extracts from the aerial parts of H. triquetrifolium. During the entire experimental period, we used extract concentrations (up to 250 μg mL(-1)) that had no cytotoxic effects, as measured with MTT and LDH assays. Hypericum triquetrifolium extracts remarkably suppressed the LPS-induced NO release, significantly attenuated the LPS-induced transcription of iNOS and inhibited in a dose-dependent manner the expression and release of TNF-α. No significant effects were observed on the release of IL-6. Taken together, these results suggest that H. triquetrifolium probably exerts anti-inflammatory effects through the suppression of TNF-α and iNOS expressions.
authors.affiliation: Research and Development Regional Center-The Galilee Society, P.O. Box 437, Shefa Amr 20200, Israel.
authors.forename: Bashar
authors.initials: B
authors.lastname: Saad
authors.forename: Bernadette Soudah
authors.initials: BS
authors.lastname: Abouatta
authors.forename: Walid
authors.initials: W
authors.lastname: Basha
authors.forename: Alaa
authors.initials: A
authors.lastname: Hmade
authors.forename: Abdalsalam
authors.initials: A
authors.lastname: Kmail
authors.forename: Said
authors.initials: S
authors.lastname: Khasib
authors.forename: Omar
authors.initials: O
authors.lastname: Said